Taming Acoustics in a Car
When taming the acoustics in a car as part of an audio upgrade, it is important to appreciate the difference between “sound proofing” and “sound absorption”. In most vehicles, both need to be addressed.
When a vehicle is in motion, its inside space is filled with sounds associated with that motion. Engine noise is often considered to be the big one. However, road noise, generated by the tyres on tarmac, and wind noise are also huge contributors to cabin noise. Many of us are keen that we do not annoy the neighbours with our audio upgrade and so an added element of “sound proofing” is required to stop sound escaping out of the car.
Taking a look at the Skinz range of sound treatment products reveals that there are major differences between them, as they all do different jobs. The starting point is always sound proofing. If we do not reduce the amount of sound getting into and out of the vehicle, we are fighting a losing battle.
Sound proofing requires using as big a density “wall” between the noise source and the vehicle interior. Glass is not bad at doing this, as it is very dense although, double glazing is better but not always practical for a vehicle. Metal work is the obvious weakness.
Metal panels on a vehicle are made thin in order to keep weight and cost down. The thin metal panels are strengthened with bracing and all manner of convolutions intended to stiffen the panels. Skinz sound deadening adds mass to the metal work and this is by far the best way to prevent sound from passing through it. it also adds stiffness which prevents the metal from moving about or vibrating so much.
Simply adding Skinz sound deadening sheets to the interior of the body work of a vehicle (especially a panel van) can make a huge difference to the driving experience. There is a trade off of course and that is weight. You cannot increase density without adding weight.
An unfortunate bi-product of adding density is it traps more sound inside and creates more internal reflections. This is where “sound absorption” comes to the fore. Sound absorption literally collects sound and disperses it within soft surfaces. Various products are used for this purpose. In the Skinz range, Wave Diffuser is the most used product for this. However, its role is mainly to treat sound emanating from behind your speakers. this prevents the sound from bouncing back from the panels behind and upsetting cone movement. The inspiration for this product comes from “egg box” sound proofing used to treat listening rooms especially in recording studios.
The final product within the Skinz range is Panel Liner. This does add a little density to panels but its main purpose is again sound absorption. This is used on all flat panels usually on top of the Skinz Sound Deadening product. Within the range are different thicknesses of panel liner and sound deadening sheets. A solid floor panel or rigid roof may not need as thick a layer as a wobbly door or wall panel and so, weight can be saved when looking at the vehicle as a whole.
To find out more about sound treatment and the Skinz range in particular, contact your local FOUR MASTER.
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